1. Field of the Invention
The present invention is directed to a wire coiling apparatus with a recovery device for a coiled wire reel, comprising a reel basket formed by basket rods standing at right angles on a base-plate that is rotatably drivable around a stationary vertical bearing and a reel support mandrel which can be lowered from the top upon and lifted off of the baseplate consisting of a star-shaped plate insertable into recesses in the baseplate, mandrel rods standing on this star plate and a guide dome connecting the free ends of the mandrel rods. The mandrel rods in the inserted position stand in between the basket rods so that the upper free ends of the basket rods are connectable with the guide dome.
Two fundamental problems are encountered in the operation of wire coiling mechanisms of this type: If greater reel weights with correspondingly greater reel height are coiled on the coiled basket, then longer basket rods are required. With such longer basket rods, centrifugal force produces bending stresses at the clamping point of the rods in the baseplate, which can no longer be carried if the construction and dimensioning of the basket rods specified in the design are observed. The other problem resides in the difficulty in pulling the finished coiled wire reel vertically upwards from the basket rods by means of the reel support mandrel introduced in between the basket rods of the reel basket, since the wire coils embrace the basket rods with a more or less great tension and this tension is additionally increased because of cooling and contraction of the wire reel.
In a known design of a wire coiler (EP - PS 74 760), these two problems are solved by articulating the basket rods in such a way on the baseplate, that they are pivotable from their vertical coiling position forming the coiler basket inwardly into an external non-coiling position. Also, that locking elements with wedge arrangements are provided at the support dome, which lock the free ends of the basket rods with the guide dome and thus retain it in their vertical coiling position, and then subsequently effect a pivoting motion of the basket rods inward out of the coiling position for the wire reel extraction process. Thus created is the possibility of recovering the coiled wire reel without difficulty by means of the reel support mandrel from the coiler basket and to bring same upwards out of the wire coiling apparatus, since by pivoting the basket rods inward the squeezing effect of the wire coils is cancelled.
The disadvantages of this known embodiment are to start off with that the basket rods cannot be inserted tightly into the baseplate, instead they require a more or less unstable guide rod fastening to the baseplate and furthermore that the free ends of the basket rods, as well as the corresponding segments of the guide dome of the reel support mandrel require comparatively complicated and technically cumbersome locking elements which additionally have to be provided for every one of the basket rods. The satisfactory cooperation of these locking elements is impaired by the heat radiated from the hot wire reel, which easily leads to deformation of the locking elements. Furthermore, the scale falling upon the baseplate from the wire during the coiling process can very easily penetrate into the gaps within the baseplate required for the movement of the basket rods, thereby interfering with the free pivoting motion of the basket rods. The lack of a firm clamping of the basket rods in the baseplate leads, in spite of the locking of the free ends in the guide dome, to a shaking movement of the whole machinery during the coiling process which limits the coilable reel heights.